Electrode support for cathode-ray tubes



Sept. 22, 1959 c H PM N ET AL 2,905,846

ELECTRODE SUPPORT FOR CATHODE-RAY TUBES BY (elves/M45 l4/a'aa-Maae Sept. 22, 1959 (5, c, CHAPMAN ETAL 2,905,846

ELECTRODE SUPPORT FOR CATHODE-RAY TUBES Filed March 29, 1956 2 Sheets-Sheet 2 United States Patent ELECTRODE SUPPORT FOR CATHODE-RAY TUBES George C. Chapman, Lawrence V. Pfaender, and H. Holscher, Toledo, Ohio, assignors to Owens-Ill1no|s Glass Company, a corporation of Ohio Application March 29, 1956, Serial No. 574,791

4 Claims. (Cl. 31378) The present invention relates to cathode-ray tubes and more specifically to cathode-ray picture tubes for color television transmission and reception.

The development of color television picture tubes has been hindered by the stringent requirements of precise alignment of internal components, particularly the colorproducing elements mounted within the face plate portion of the tube. An apertured electrode structure such as a shadow mask or line grid is usually disposed adjacent to the screen control electron impingement upon phosphors of three primary colors. The electrode structure frequently consists of a heavy frame and bulky clamping mechanism, both of which add to the difiiculty of tube assembly and exhaust. The location of the apertured electrode must be carefully controlled with respect to the phosphor screen in each individual tube for proper color registry.

An object of this invention is to provide an improved supporting structure for an electron beam deflecting element of a cathode-ray tube for directing and accelerating the electrons of the beam onto respective color areas of the tube screen.

Another object of this invention is to provide novel support means for an electrode element of a cathode-ray tube which means are radially disposed about the inner periphery of the face plate and which are adapted to permit control of the tension applied to the wire-like elements of the grid.

Another object of this invention is to provide support members partially embedded within the annular flange of a glass face plateand fusedly attached thereto for the support of an electrode element of a cathode-ray tube.

Another object of this invention is to provide an improved grid support structure attached to the interior of the glass face plate of a cathode-ray tube, which structure is of simple construction with a design applicable to existing and proposed types of picture tubes.

The specific nature of this invention, as Well as other objectives and advantages thereof, will become apparent to those skilled in the art from the following detailed description taken in conjunction with the annexed sheets of drawings on which, by way of preferred example only, are shown two embodiments of this invention.

On the drawings:

Fig. 1 is a vertical sectional view of a glass face plate for a cathode-ray tube envelope.

Fig. 2 is an enlarged vertical sectional view taken along the line 2-2 of Fig. 1.

Fig. 3 is a vertical sectional view. similar to Fig. 1 illustrating a structure for supporting a line grid.

Fig. 4 is an enlarged vertical sectional View taken along the line 4-4 of Fig. 3 illustrating a single hook Patented Sept. 22, 1959 The present invention is applicable to a cathode-ray tube envelope of which only the glass face plate portion 10 is illustrtated in Fig. 1. The face plate portion 10 comprises a bowl-shape closure member having a uniformly curved viewing window 11 located in its central area. The viewing window 11 may be either round or rectangular in shape and is bounded by an annular flange 12. The flange 12 is normally disposed on the concave side of the viewing window 11 and terminates at a planar sealing edge 14. A screen 13, composed of phosphorescent materials which are well-known in the art, is peposited on the inner surface of the viewing window 11.

A series of stud members 15 are radially disposed around the inner surface of the flange 12 in spaced relationship. The stud members 15 are arranged in a common plane for supporting a color-control element such as a shadow mask (not shown) or similar apertured electrode. Each of the stud members 15 has two or more prongs 16, the end portions 17 of which are embedded in the glass flange 12. The stud members 15 are attached so that the interior surface 18 of each is substantially parallel to the tube axis. An internally threaded opening 19 is provided in the central portion of each stud member 15 to receive a bolt 25 located on the periphery of the color-control structure. Stud members 15 may be similarly employed to support strip member 26 by bolts 25 inserted into threaded openings 19 with expansible washers 27 therebetween.

The stud members 15 provide a method of fastening which does not require any drilling of holes in the glass or distortion thereof in their mounting. The small prongs 16 are so designed so as to attach to the glass in a softened condition by simply pressing them therein. The installation of the stud members 15 may be facilitated by, a fixture or jig which is set to move the stud members 15 outward into the heat-softened flange 12 in a fixed geometric pattern. The prongs 16 may be individually rather weak, but in combination furnish strength to each stud member 15. Furthermore the use of prongs 16 eliminates any possible problem of glass-to-metal matching because any possible stress is spread over a large area. The prongs 16 may consist of wire which is weak enough to allow for some distortion as the glass cools.

Another use of the stud members 15 as shown in Fig. 3 consists of mounting strip members 21 on two opposing sides of the flange 12 in a lengthwise direction with bolts 20 passed through clearance holes in the strip members 21 and inserted into the threaded openings 19. Strip members 21 have either a single or double row of hooks 22 spaced apart from and parallel to the cylindrically shaped window 11 for retaining a gridtype electrode.

Another modification of the present invention consists of mounting a plurality of nuts 23, such as shown in Figs. 4 and 5, in spaced relationship partially embedded in the flange 12 with each having an internally threaded opening 24 exposed. The nuts 23 may be either radially. p0- sitioned in a uniform pattern around the flange 12 or located along two opposing sides thereof, as indicated in Fig. 3, at the positions of the bolts 20 for supporting two or more strip members 21. The nuts 23 are composed of a material which has coeflicients of thermal expansion and contraction compatible with the glass for the avoidance of objectionable stress patterns'in their installation.

Where only one strip member 26 is required on each of the opposing sides of the flange 12 to support a single grid circuit, a row of nuts 23 is embedded in the flange 12 for the retention of bolts 25 such as shown in Fig. 4. An insulating and expansible spacing washer 27 is interposed between strip member 26 and embedded nut 23 to permit adjustment of the relative position of the strip member 26 with respect to nut 23. A series of U-shaped hooks 28 of proper amplitude for forming a single grid circuit is formed i i a lengthwise direction along one free edge of the stri member 2'6 as shown in Figs. 4 and 6. Stud members may be [similarly employed to support strip member 26 by bolts 25 in serted into threaded openings 19 with ex ansi'ble washers 2 7 therebetweeii.

In order to support a twin hook construction on each of two opposing sides of the flange 12, two strip mem-' bers 26 and 30 arel'ocated in parallel alignment placed near, although not in contact with each other, assnewn in Fig. 5. Either a. single or double row of embedded nuts 23 may be employed to support the two strip members jointly or independently as required, A bolt 29 composed of electrically insulating material is used to retain strip members 26 and 30 by passage through clear ance holes therein and insertion into the nut 23. The strip member 30 is separated from strip 26 and the nut 23' by a spacer 32 and expans'ible washer 27 respectively, both of which are composed of electrically in-' sulatiiig material such as glass or plastic coated metal. The spacer 32 may also be composed of resilient material that the relative positions of strip members 26 and so are adjustable. Strip member so has a U-shaped series of hooks 31 along one of its free lengthwise edges which are fitted within the somewhat similar although deeper U-shape'd series of hooks 28 of strip member 26. The hooks 28 and 31 are alternately spaced with respect to eachother and the deeper hooks 28 have depressed areas 35 on their extremities to facilitatethe passage of grid 34 extending from hooks 31.

A grid of snbstar'itially equidistant parallel wires 33" is looped around the necks-12s and dissected and one circuit to form a single electrode. Anothenser'ies of parallel grid wires 3'4 is'wound around the hooks 31 alternately spaced in approximatelythe same plane and equidistant from the grid wires 33. The grid wires and 34 each form electrically independent circuits which are 'dofinccfed to terniin'als so that an electricaI potential said viewing portion, a plurality of metallic mounting members secured to the inner surface of said flange in spaced relationship and in substantially a common plane normal to the axis of said flange, securing means comprising a plurality of thin deformable prongs extending from each of said mounting members with their extremities embedded withiii and fusedly attached to said flange, each of said mounting members being formed with a threaded opening on the inner surface thereof adapted to support an electronic element Within said flange by contas ing engagement therewith.

2. A holldw glass' face plaster a cathode i'ay tu'be comprising a curved viewihg pdrtion and mi annular glass flange pdrtion extending around the periphery of said viewing portion, a luminescent screen on the inner surface of said viewing portion, a pliirality of metallic mounting members afiixed to the interior of said flange in spaced relationship with their axis normal to the st sa'id flaii'gc, each of said mounting' meinbers having a plurality of at least two' spaced-apart thin deform-T able prongs fusedlyemhedde'd within and attached to said flange, saidrr'ioiintiiig members each having an exposed opening in its inner surface adapted to retain an electroncor'itrblling 'striictiire, Q h I I I p 3; A hollo'w' glass face plate for a eathode ray tube comprising a curved viewing portion and an annular glass flarig'e portion exteiidirig around the periphery of said viewing p ni a phosphorescent screen on the inner surface of said viewing portion, a pliirality of metallic may be impressed upon each individually for cbntlrolling and accelerating electron impingement. The gridwires 33 and 34 usually have a fine diameter of approximately the same widthas the lines of phosphorescent materials of the screen 13.

As stated it is contemplated that the strip members and 30 may be separately attached to the flange 1-2 by two rows of bolts 25' and 29 respectively fitted into separate rows of embedded nuts 23. Thus fine grid wires may be individually wound on separate pairs of hooks 2'8 and 31 while each pair is supported by a stiff fixture separated from the face plate 10. The fixture retains the grids in the same prefabricating position as their alignment with the embedded nuts 23. Following completion of the winding, the strip members 26 and" 30 are introduced into" the face plate" 10 and attached by the bolts 25' and 29' after' which the fixture is with drawn leaving the gridssecur'ed in place. Alternatively, the grid wires 33 and 34 may be wound after the strip members 26 and 30 are secured in place within the face plate 10. The bolts 25 and 29 facilitate rapid andcornplete removal of the electrode structure for its replacement or realignment as required. This form of electrode readily'lends itself to economical manufacth're for numerous types ofpicture tubes.

Additional modifications-may he resorted to within the spirit and scope of the appended claims.

l. A hollow'glass face platefor a cathode-ray tube comprising a' curved glass viewing portion and an annular glass flange portion extending around the periphery of stud moiiiitin'g members dispo's ed at'right angles to said aaag'eeach ha fig a plurality of relatively thin deform} able prongs partially'embedded within fus'edly at sense as said flarrge ertiqn'aleng two opposing interior surfaces thereof, a plurality of thin ar cuate strip mcm' bers mounted upon the stud members disposed along each of said opposing interior surfaces, s'aid strip members being in shamans-11 parallel alignment with said screen, a series of books fortified in a lengthwise direction along a nee edge er each of'said snip members, ar'idtwo elec trically independent electrodes consisting of fine wires str'hng between stid seriesjof hooks on opposite pairs of said mem'b'ers" with the Wires of the electrodes alternately spaced. W

,4. hollow glass face plate for a cathode-ray tnbe comprising a curved viewing" portion and an annular glass" flange portion extending around the periphery of said viewing portion, a phosphorescent screen on the inner surface of said viewing portion, a plurality of metallic st n d moiintihg members disposed at right angles to said flange each" having three thin deformable wire-like eleni e nt's disph'sed iii a triangularipat'terrr partially embedded in flis'edly attached to' said flange portion along two oppdsing interior surfacesthereof, a plurality of thin slightly curved strip members mounted upon the stud membersdisfidsed aisag each of said opposing interior surfaces in an archate patterm'sa'i'd strip members being in siibsjt antially parallel alignment with said screen, a series of hooks formed in a lengthwise direction along a free edge of each of said strip members, two electrically indeperident electrodes consisting of fine wires strung be tween said series of hooks on opposite pairs of said strip members with the wires of the electrodes alternately spaced and means to adjust said strip: members relative to each other to thereby control the tension in said electrode wires.

Refernees Cited in the tile of this patent UNITED STATES PATENTS Henry Jan. 28, 1958 

